According to The Conclave it is a repository of knowledge from an ancient civilization.

Hel’con interfaced with the device and after disabling a VI program that was designed to teach all of galactic history in a 20 year period he found a backdoor where Uro-HERALD resided. He discovered that an AI consciousness, HERALD resided here and had no memories of what his purpose is. Urodotros came in and got trapped in here. A force came inside The Cube and was destroying everything forcing HERALD and Uro to merge minds in order to preserve each other.

Was plugged in to a data repository on Valkon City on Mars, restoring a part of itself.